I have used 10w30 full synthetic Amsoil on both gen 1 & 2 cars for 5 years with no problems. 30w is 30w. The 10w is thicker cold than 5w. Only diff. I don’t know where you’re located but in anything above 25f or so should be fine. Especially if you don’t crank it cold and immediately stomp it to the floor. But yes, no matter what you choose always use full synthetic.